Toglia was removed from Friday's game against the Diamondbacks with a dislocated right shoulder, C. Trent Rosecrans of The Athletic reports.
Stephenson is not in the Reds' starting lineup against the Diamondbacks on Friday.
The Reds activated Santillan (oblique) from the 15-day injured list Friday.
The Reds optioned Maxwell to Triple-A Louisville on Friday.
Burke (5-5) was credited with the loss and a blown save to St. Louis on Thursday, when he allowed six unearned runs on two hits and three walks while striking out one.
Pagan was not used to close out a 5-4 lead in the ninth inning of Thursday's 10-9 loss to the Cardinals.
McLain went 1-for-4 with a grand slam, a walk and an additional run scored in Thursday's 10-9 loss to the Cardinals.
Singer took a no-decision against the Cardinals on Thursday, allowing four runs on five hits and one walk in six innings. He struck out three.
The Reds outrighted Emanuel to Triple-A Louisville on Thursday.
Suarez is absent from the lineup for Thursday's game versus the Cardinals.
